Field of the Invention
Embodiments of the present invention generally relate to techniques for representing an input curve on a display, more particularly, to a method and apparatus for evaluating a spline constant to enable optimal sampling of user input curves.
Description of the Related Art
In order to estimate the motion performed by a user, curves input via mouse on a computer or laptop, or through touch input on a tablet device are sampled by software in the operating system of the device onto a discrete grid. The discrete grid is used to generate spline curves representing each discrete portion of the user's input motion. Each spline curve is created using control points and a stiffness parameter used to control the curvature of the spline. When reproducing at the sampling resolution, the sampled curve represents a visually close match to the original input curve. However, when the display resolution is changed by zooming in on the curve, the sampling frequency becomes inappropriate for display, resulting in excessive rendering overhead and visible staircase-like artifacts. This occurs because the spline curves created for representing each discrete portion of the user's input motion are represented poorly by their control points and stiffness parameters resulting in jagged curves.
Therefore, there is a need in the art for a method and apparatus for evaluating spline parameters for smooth curve sampling, wherein optimal results are guaranteed.